The lowest pressure of any storm we've seen in the atlantic basin. After nyu hospital here in manhattan was plunged into darkness, its generators failing. Hundreds of parents have been evacuated to other facilities, 20 ofhem babies. David muir's been on the scene overnight. David? Reporter: George, you talk about the resiliencef new yorkers. And it's playing out still at this hour. You see the long line of ambulances around the block. That's a patient that's been taken out of the hospital. You can see if you pan over to 1 of the patients, over 200 taken from the hospital overnight. And this is a rescue effort that continues to unfold at this hour. You see the long line of ambulances here. As you mentioned, there were 20 babies from the neonatal intensive care unit that were brought downstairs. One of the things that the fire department had to do was to bring in sleds to carry them down the stairwell to bring them down. There were several patients that were critically ill. 40 to 45 of them taken to area hospitals. We're told they're going to be cared for, obviously, once they arrive there. As you can see, this line of ambulances, and there's been a line since 10:00 last night, when the generators failed. This is the hospital over my shoulder here. It's completely dark. They're trying to figure out how so many of the generators could have failed. Big questions about how they get the fuel to the generators. The work of heroes. I saw one to saw me here and gave me a thumbs up. Never seen a line of ambulances there. Let's go to josh, now. Staggering images. We talked a lot about it.

This transcript has been automatically generated and may not be 100% accurate.

Superstorm Sandy Storm Surge in New York City

Chris Cuomo reports on the aftermath of the storm in the Big Apple.

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